The purpose of this training program in endocrinology and metabolism is to provide an opportunity for promising post-doctoral individuals of exceptional quality to train for careers in academic endocrinology and biomedical research. The Program has been supported by this training grant mechanism for over 45 years and presents a record among its graduates of superb training and major academic achievement. The central features of the Program include intensive research in the laboratory of the participating faculty member and didactic exposure to basic science and clinical investigation. Research areas span a wide range of endocrinological disciplines with centers of excellence in neuroendocrinology, metabolic bone diseases, diabetes, reproductive endocrinology, endocrine genetics, lipoprotein metabolism, molecular endocrinology, endocrine protein and glycoprotein chemistry, and signal transduction. The scientific methods of the faculty include classical endocrinological techniques of basic and clinical investigation as well as the most modern biochemical and molecular studies of hormone action. Expertise in biochemistry, cell biology, molecular biology, mouse genetics, and physiology are all well-represented by the faculty. Highly experienced clinical investigators provide expertise to fellows in a wide variety of subspecialties with neuroendocrinology, metabolic bone diseases, diabetes, and lipoprotein metabolism featured as particular strengths. Primary facilities are centralized in the Division of Endocrinology in the Department of Medicine. Participating laboratories outside the Division of Endocrinology extend opportunities for endocrinology training to laboratories in the Departments of Physiology and Biophysics, Genetics and Development, Pediatrics, Microbiology, Anatomy and Cell Biology, Pharmacology, and Nutrition. Trainees are selected from a very competitive pool of applicants after a thorough review of their credentials and interviews with the directors of the Program. Fewer than 2% of applicants are selected. The majority of trainees go on to careers in investigative endocrinology. The Program focuses upon applicants who hold the MD or MD/PhD degree and have a strong interest in or prior exposure to research.